What kind of prepayments? Estimated payments? Just pay directly online to the IRS and your state. No form necessary.
Here are the blank estimate forms and instructions for federal. You need to go to your state's website to get theirs.
https://www.irs.gov/pub/irs-pdf/f1040es.pdf
Or you can pay directly on the IRS website https://www.irs.gov/payments
Be sure to pick the right kind of payment and year.....2024 Estimate